TPS Voltage Low

Does anyone have an Idea on what may be causing the TPS to have low Voltage on a 98 Amigo? we have change the TPS Sensor and cleaned the EGR. Reset computer but it still has the Code P1122. IT make the Truck fall on its face "Chugs" when at a consistant speed or going down a hill. Also Changed the fuel Presure regulator. Could it be a Speed Sensor?


Thanks
Kelly

did you clean the EGR tube?

How old is the fuel filter?

I did not try the tube, do they plug often? and not sure about the filter, I could try that too.

Thanks Kelly